The present invention relates to an apparatus for the thermal treatment of a textile web. Such an apparatus includes at least one drum or cylinder with a perforated outer casing surface, around which a material web is at least partially wound, wherein a patterning or structured shell with a multitude of openings separated by ridges can be fitted onto the outer casing of the drum.
Methods for the thermal treatment of a textile web of fibrous material or nonwoven include the drying and/or hardening with hot air in a rapid-packager drier, also referred to as a flow-through hot-air drier, in which a heated gas, for example air, flows through the material web, thereby resulting in a drying or hardening. Driers or thermobonders, which comprise one or several drums arranged inside a housing, are known for the drying and hardening of textile webs. A textile web, supplied via an opening in the drying chamber to the drier, wraps itself around a large portion of the drum circumference and is guided around the following drum and/or exits the drying chamber once more. While wrapped around the drum, the material web is subjected to treatment. The treatment may comprise blowing in fresh air that flows through the web and the drum, thereby absorbing moisture from the material web. The material treatment may also include a thermal bonding of the material web as a result of the hot air and/or gas flowing in which can at least partially melt the fibers, which can consist of polyamide, into each other. Additionally, the material web may treated with hot steam.
A smooth, non-structured fibrous material or nonwoven is generally created in the process which can be used, for example, as topsheets for slip inserts. For a change in the product type that requires a structuring of the fibrous material, the patterning shell on the drum must be replaced. The depth of the patterning in the fibrous material depends on the thickness of the casing surface for the patterning shell. However, replacing the patterning shells is very involved since the complete patterning shell must be removed along the longitudinal axis of the drum. Depending on the working width, the patterning shell can have a diameter of up to 4 m and a length of up to 4.5 m. This process is very time-consuming and requires a lot of personnel. Further, the thermobonder is not available for a longer period because of the retooling measures which may include removal of parts of the housing.